All recent models of iPad support TouchID or FaceID - but not both. FaceID is a feature of iPad Pro models; other models of iPad and iPad Air all feature TouchID.
As for your difficulties with TouchID, start here:
Some users just have difficulty using TouchID. The causes for of TouchID being unreliable for some users - and not others - are many. Whilst not an exhaustive list, possibilities include:
- Very high humidity (“sweaty” fingers)
- Very low humidity (excessively dry skin)
- Poor fingerprint ridge-detail (excessive hand washing - or exposure to abrasive material, damaging fingerprint detail)
- Physical injury (cuts or splits to the fingertip)
If you have naturally dry skin, try using a “light” (non greasy) and easily absorbed skin moisturiser.